Letter of recommendation: Waive your right to read the letter
Federal law grants you access to your letters of recommendation, but many applications include a form where you can waive your rights to read the letter. We highly recommend that you do so. This reassures the reader that the instructor has written a candid letter. Studies have shown that confidential letters carry far more weight. In addition, writers are far more comfortable writing a complete, candid letter when they know the applicant will not have access to the text. If you fear that the letter writer might not do justice to your achievements or might include negative information — well, that's a good sign you should not be asking that person for a letter of recommendation.
